The formation of dust particles during a polymerization process is one of the important problems in the plastic production industry. Said dust particles derived from polymer with very small particle size i.e. the polymer with particle sizes which are smaller than 75 micrometer. If the dusts particles are presence in large amount, they tend to obstruct a continuous response of the production process, thereby, affecting a translocation of the polymer in the supply tube to be stuck and damaging the production process. Generally, there are several methods to get rid of these dust particles, for example, using a sieve and a fan to blow away these dust particles, or installing a filter in the polymer production process. However, it was found that there are some limitations to of those methods in order to effectively and efficiently remove all dust particles. Moreover, utilization of those methods tends to complicate the production process as well as 1 increase production cost. Therefore, prevention or minimization of the formation of said dust particles is more preferable.
It is known that the shape and size of polymer and catalyst, and distribution of polymer are correlated with each other, as disclosed in Ludwig L. Bohm, Angew. Chem. Int. Ed. 2003, 42, 5010-5030. That is, if the catalyst has a spherical shape and a narrow particle size distribution, it would lead to the production of the same spherical shape and narrow particle size distribution of the polymer as well. Therefore, there have been efforts to improve the size and shape of the polymer through uses of the catalyst with suitable size and shape. Japanese Patent Number 6-287217 discloses a production process of an olefin polymer, which utilizes a solid catalyst compound to obtain a polyolefin with a spherical-like shape and with a narrow range of distribution diameter. Furthermore, there is no polymer that is smaller than 200 μm, produced as yet through the process which utilizes an increase of a powdered non-ionic surfactant during a catalyst preparation step in order to get rid of a formation of small size particles of said solid catalyst.
Japanese Patent Application, Publication Number 3-140308 discloses a production method of a polymerization catalyst for olefin, which is characterized in that a complex compound obtained from reacting an aluminium compound with alcohol in an inert organic solvent of which is stirred until it is mixed together at a temperature higher than its melting point by using a non-ionic surfactant, and then cooling down the suspended solution rapidly without a substantial loss of the alcohol. This results in a spherical solid composition. Then, said solid composition is partially dried, and treated with halogenated titanium or an electron donor compound.
However, the non-ionic surfactants disclosed in both Japanese Patents are surfactants in a sorbitan ester group. Use of the sorbitan ester in industrial scale can pose difficulties due to a low stability of its emulsion system and can consequently produce magnesium halide support with undesirable shape.
In order to solve this problem, the present invention aims to provide magnesium halide support and preparation for same for use as a composition of the catalyst in the olefin polymerization in order to achieve polymerized olefin with desirable spherical shape and narrow particle size distribution, as well as lower dust particles.